CN108068194B

CN108068194B - Method and apparatus for casting precast concrete products

Info

Publication number: CN108068194B
Application number: CN201710944302.8A
Authority: CN
Inventors: 拉西·耶尔维宁
Original assignee: Elematic Oy
Current assignee: Elematic Oy
Priority date: 2016-11-14
Filing date: 2017-10-12
Publication date: 2021-01-08
Anticipated expiration: 2037-10-12
Also published as: FI20165851A; RU2704399C2; US20180133923A1; EP3323577B1; CN108068194A; FI20165851L; RU2017138114A3; RU2017138114A; US10759086B2; EP3323577A1

Abstract

The present application relates to a method and an apparatus for casting a precast concrete product, in particular to a method and a device (1; 21) for casting a precast concrete product with a substantially horizontal slip casting process, wherein concrete material is fed in at least one feeding phase (2; 22, 23) to a slip casting mould (4, 5, 6) compacting and defining the product to be cast, wherein at least one component (10; 25) is embedded in the concrete material after the at least one concrete material feeding phase (2; 22, 23) and before a final compaction of an upper surface of the product to be cast.

Description

Method and apparatus for casting precast concrete products

Technical Field

The present invention relates to the placement of precast concrete products for use in building construction. More specifically, the present invention relates to a method and apparatus for casting precast concrete products using a slip-form casting process.

Background

Precast concrete products, such as hollow core slabs and solid concrete slabs, are typically cast as a continuous casting process by slip casting on a long casting bed. The length of the continuous casting process is defined based on the total length of the element to be cast or based on the maximum length of the casting bed. The length of the casting bed used in slipform casting can be up to 150 and 200m, depending on the size of the element factory. When the slip-form casting apparatus has cast a continuous slab on the casting bed, the cast concrete material is allowed to cure on the casting bed. After the concrete material has cured, the homogeneous casting element is cut into blocks of predetermined length, typically by sawing, based on the design characteristics of the already produced element, and the cut concrete element is lifted from the casting bed and stored to await transport to its intended target of use.

Several different slip-casting methods and devices are known in the art. The most common types of slipform casting methods used for casting concrete products are the extruder method and the slipform former method. In the extruder method, the concrete mixture is fed in a single feed stage from a concrete feed container to a feed screw that extrudes the concrete mixture into a slipform casting mold defined by the upper surface of the casting bed and the side and top panels of the casting machine. When casting hollow core slabs, the feed screw is followed by a core forming mandrel which forms a core in the form of a longitudinal void in the cast concrete product. Compaction of the concrete product to be poured is achieved by vibratory and/or levelling movements of the side and top plates and the formation of the core is ensured by a back and forth compaction movement of the entity formed by the feed screw and the attached core shaft. The casting machine is moved along the casting bed driven by the reaction force from the feed screw that extrudes the concrete material and optionally with an additional drive motor. As the casting proceeds, the cast product remains on the casting bed. A known extruder-type casting machine and method are disclosed, for example, in publication EP 2821192.

In the slipform-forming machine casting method, the concrete mixture is fed from the concrete material container to the slipform casting mold in at least two feeding stages. In a first feeding stage, concrete material is fed to the lower part of the casting mould formed by the top surface of the casting bed and the side plates of the casting machine. A first feeding stage of the concrete mixture is followed by a vibrating shoe and a core forming mandrel which compacts the cast concrete mixture by vibrating the concrete mixture and forms the final shape of the lower part of the concrete product to be cast. In a second feeding stage, the concrete mixture is fed onto the end of the core forming mandrel and onto the previously cast concrete mixture for casting the upper part of the product to be cast, after which the concrete mixture is compacted with a vibrating plate which defines the upper surface of the slip-form casting mould and which is located at the rear of the casting machine. As the casting progresses, the cast product remains on the casting bed.

Slip casting is commonly used for casting long products with a uniform cross section, such as large blocks or hollow slabs, which are cut to a predetermined length after the cast concrete has cured.

Prefabricated slip cast concrete products are often also provided with prestressed strands, which provide additional strength to the concrete product and thus increase the load-bearing capacity. Slip-cast concrete products are commonly used to form horizontal intermediate floors and similar structures in buildings. In addition to hollow slabs or massive slabs, slipform cast products can be formed into poles, pillars, ribs, etc.

Different kinds of additional reinforcements and other items, such as lifting loop forming parts and welded plates, can be fixed to the prestressing strand before casting, but this is often time consuming and the pressure of the concrete material, especially in extruder slip casting, may displace these parts. Thus, many of these additional components are added to the slip cast concrete product after casting, either manually or with different finishing machines.

Furthermore, slipform casting molds typically limit the addition of reinforcements and other components to the prestressed strands extending from the outer surface of the slipform cast product. One solution to this problem is to use a segmented upper surface of the slipform casting mold, wherein the segments can be arranged at a suitable distance apart, allowing the reinforcement and other pieces to pass through the slipform casting mold and thus through the entire slipform casting machine. Such a solution is disclosed in publication EP 3056328.

Disclosure of Invention

The present invention provides a novel method and apparatus for slipform casting or concrete products in which the addition of reinforcements and other components to be at least partially embedded in the slipform cast product is accomplished prior to final compaction of the slipform cast product. This significantly speeds up the manufacturing process as the need to embed these components after compaction of the concrete product is eliminated or at least significantly reduced.

In the method of the invention for casting a concrete product with a substantially horizontal slip-casting process, concrete material is fed into the slip-casting mould in at least one feed stage, the slip-casting mould compacts and defines the product to be cast, and at least one component is embedded in the concrete material via the upper surface of the product to be cast after the at least one feed stage and before the final compaction of the upper surface of the product to be cast.

The final compaction of the product to be poured is obtained by the oscillating movement of the compaction beams and the floating movement of the side plates. Additional compaction is obtained from the floating motion of the hollow core forming tube as the hollow core slab is poured. The vibrocompaction motion can be replaced by a troweling compaction motion and vice versa, and a combination of troweling and vibrocompaction motions can also be used with surfaces that bound the slipform casting mold.

In an embodiment of the method of the invention, the at least one part is only partially embedded in the concrete material and passes through the slipform casting mould through a gap in the top surface of the slipform casting mould. In this embodiment, the top surface of the slip-form casting mold comprises two or more sections separated by the gap.

In an embodiment of the method of the invention, the at least one component is a stiffener or a lifting loop forming part. Other components can also be embedded into the product to be cast using the method of the invention, such as fixing components for short walls, fixing components for stays used during installation of the concrete product, fixing components of safety mechanisms or bushings with internal threads, for example. The material of these parts is usually metal, for example steel, but they can also be made of other strong materials, in particular reinforcing ribs, such as basalt fibres or carbon fibres.

In an embodiment of the method of the invention, the concrete product to be poured is a hollow core slab and the at least one component is embedded in the area of the web between the hollow cores.

In an embodiment of the method of the invention, the at least one component is embedded in a longitudinal end region of the product to be cast. This allows for the quick and cost-effective manufacture of end-reinforced concrete slabs.

In an embodiment of the method of the invention, the method is an extruder-type slip casting method or a slip-former-type slip casting method. Different kinds of combinations or variants of the extruder-type slipform casting method and the slipform former-type slipform casting method can also be used with the present invention.

Furthermore, in an embodiment of the method of the invention, the embedding direction of the at least one component is adjustable, so that the orientation of the component in the product to be poured can be changed to suit different applications. This allows the components to be embedded in the same concrete product to be cast at different positions and in different orientations, such as for example on the end regions of the concrete product to be cast. For example, the change in the embedding direction can also depend on the position of the casting machine on the casting bed or on the casting distance.

The invention also provides an apparatus for casting a concrete product using a substantially horizontal slip-casting process, wherein the apparatus comprises means for feeding concrete material to a slip-casting mould compacting and defining the product to be cast in at least one feeding stage, the apparatus further comprising means for embedding at least one component in a concrete block via an upper surface of the concrete product to be cast after said at least one feeding stage of concrete material and before a top surface of the slip-casting mould compacts an upper surface of the product to be cast.

In an embodiment of the apparatus of the present invention, the slip-form casting mold comprises a top surface divided into sections with a gap between the sections for allowing the partially embedded part to pass through the slip-form casting mold.

In an embodiment of the apparatus of the invention, the apparatus comprises a hollow-core forming device, such as a hollow-core forming mandrel.

In an embodiment of the apparatus of the invention, the embedding direction of the means for embedding the at least one component in the concrete material is adjustable. This allows embedding the components in the same concrete product at different positions by tilting the means for embedding the at least one component during the casting process, such as when casting a reinforced concrete slab in which the angle of the embedded components is opposite, for example at different ends of the slab. The change of the embedding direction of the device can be achieved, for example, depending on the position of the casting machine on the casting bed or the casting distance.

Furthermore, in an embodiment of the apparatus of the invention, the apparatus is an extruder-type slipform casting machine, wherein the concrete material is fed from the concrete material storage tank into the slipform casting mold with at least one feed screw in a single feeding stage, or the apparatus is a slipform former-type slipform casting machine, wherein the concrete material is fed from the concrete material storage tank into the slipform casting mold in at least two stages, or the apparatus is a combination of an extruder-type slipform casting machine and a slipform former-type slipform casting machine.

Drawings

Exemplary embodiments of the present invention and their advantages are explained in more detail below and with reference to the drawings, in which

Figure 1 schematically shows an embodiment of the apparatus of the invention,

figure 2 schematically shows an alternative embodiment of the device of the invention,

fig. 3 schematically shows an embodiment of an embedding means for the device of the invention, and

figures 4A-4D schematically show examples of components embedded in a concrete product using the apparatus of the invention.

Detailed Description

In fig. 1 an embodiment of the apparatus of the invention is shown, which is an extruder-type slip-form casting machine 1. This casting machine 1 includes: a concrete material storage tank 2 from which concrete material is fed to a feed screw 3, the feed screw 3 extruding the concrete material into a slip-form casting mould formed by a casting bed 4, side panels 5 and a top compaction beam 6. When casting a Hollow Core Slab (HCS), the feed screw 3 is followed by a hollow core forming mandrel 11. The casting machine 1 is moved along the casting bed 4 via the rails 7 by means of wheels 8, being propelled in the direction of the arrow by the reaction force of the feed screw 3 with the aid of a drive machine (not shown).

The casting machine 1 comprises an embedding device 9 for embedding the component 10 into the concrete product to be cast. The position of the embedment device 9 can be adjusted by tilting the embedment device 9 relative to the casting machine 1 so that the orientation of the embedment components 10 can be adjusted in the concrete product to be cast. The tilting preferably takes place about a tilting axis which extends horizontally perpendicularly with respect to the casting direction. This allows embedding the component 10 in different positions in the same concrete product to be cast by tilting the embedding means 9 during the casting process, such as when casting concrete slabs in which the angle of the embedded component is opposite, for example at different ends of the slab. In this solution, the inclination of the embedding device can be realized, for example, depending on the position of the casting machine 1 or depending on the casting distance. The operation and construction of the illustrated embodiment of the embedding arrangement 9 will be discussed in more detail later with respect to fig. 3.

In order to allow the upper end of the insert part 10, which extends above the upper surface of the product to be cast, to pass through the slipform casting mould, the top compacted beam 6 is formed as sections, wherein the gaps between the sections extend in the casting direction through the area of the compacted surface of the beam at the location of the insert part.

In fig. 2 an alternative embodiment of the apparatus of the invention is shown, which in this embodiment is a slip-form-machine type slip-form casting machine 21. In this embodiment the concrete material is fed into the slip-form casting mould in two feeding stages, in the first feeding stage via a feed hopper 22 and in the second feeding stage via a feed hopper 23. The casting machine 21 is moved along the casting bed via the rail in the direction of the arrow in the figure under the urging of the drive mechanism.

The casting machine 21 comprises an embedding device 24 for embedding the component 25 into the concrete product to be cast. In this embodiment, the embedding takes place after the first concrete material feeding stage and before the second concrete material feeding stage. The embedment device 24 is advantageously rotatably fixed to the casting machine 21 so that the orientation of the embedment members 25 may be adjusted in the concrete product to be cast, such as discussed with respect to the embodiment of fig. 1.

In this embodiment, the top surface of the slip-form casting mould is also advantageously divided into sections, so that the part of the part extending from the upper surface of the product to be cast can pass through the slip-form casting mould when the part 25 is only partially embedded in the product to be cast.

Fig. 3 schematically shows an embodiment of the embedding arrangement 9, 24 of the invention. In the present embodiment, the embedding means 9, 24 comprise three main parts: a storage bin 31; a feeding portion 32; and an embedded portion 33.

The storage magazine 31 is intended for storing a plurality of components to be embedded in the product to be cast and is equipped with means 34 for feeding the components one by one into the feed portion 32. The device 34 can be realized, for example, with a suitable conveyor belt.

Once the component is fed from the storage bin 31 into the feeding portion 32, it is transferred to the embedding portion 33 with the transfer device 35. The transfer device 35 can be realized, for example, by a pusher moved by a hydraulic cylinder.

The component located in the embedding part 33 is then pushed out of the embedding device 9, 24 and embedded with the embedding device 36 in the product to be cast in the desired position and at the desired depth. These embedding means 36 can be realized, for example, by a pusher moved by a hydraulic cylinder.

The operation of the embedment means 9, 24 is also advantageously controlled by an automatic control system controlling the casting process of the slipform casting machine 1, 21. This enhances the correct positioning of the components embedded in the product to be poured.

Fig. 4A-4B schematically show examples of components embedded in a concrete product with the apparatus of the invention. Fig. 4A and 4B show examples of reinforcing ribs, and fig. 4C and 4D show examples of parts forming a lifting ring.

Since in the present invention the component is embedded into the concrete product before the final compaction of the product is achieved, the part section located within the product to be poured can be formed to contain a larger section, so that a good shape based attachment and anchoring of the component to the concrete can be obtained. Furthermore, the compaction that occurs after the embedding of the component also allows for a better attachment of the concrete material to the component over the entire embedding length of the component.

The material of the component is typically a metal, such as steel, but other high tensile strength materials, such as basalt fiber materials, may also be used.

The specific exemplary embodiments of the invention that are illustrated in the figures and discussed above are not to be construed as limiting. The embodiments may be modified and adapted in many obvious ways by a person skilled in the art within the scope of the appended claims. The invention is thus not limited to the described embodiments.

Claims

1. A method for casting precast concrete products with a substantially horizontal slip casting process, wherein concrete material is fed in at least one feed stage to a slip casting mould (4, 5, 6) which compacts and defines the product to be cast,

characterized in that at least one component (10; 25) is embedded in the concrete mass via the upper surface of the product to be cast after the at least one feeding phase and before the final compaction of the upper surface of the product to be cast,

wherein the embedding direction of the individual embedding devices (9; 24) for embedding the at least one component (10; 25) in the concrete material is adjustable and the position of the embedding devices is adjusted by tilting the embedding devices, which tilting takes place about a tilting axis which extends horizontally and perpendicularly with respect to the casting direction.

2. Method according to claim 1, wherein the at least one part (10; 25) is only partly embedded in the concrete material and passes through the slipform casting mould (4, 5, 6) through a gap in the top surface (6) of the slipform casting mould.

3. Method according to claim 1 or 2, wherein the at least one component (10; 25) is a reinforcement bar, a lifting ring formation, a fixing component for a low wall, a fixing component for a stay used during installation of the concrete product, a fixing component for a safety mechanism or a bushing with an internal thread.

4. A method according to claim 1 or 2, wherein the concrete product is a hollow core slab and the at least one component (10; 25) is embedded in the area of the web between the hollow cores.

5. A method according to claim 3, wherein the concrete product is a hollow core slab and the at least one component (10; 25) is embedded in the area of the web between the hollow cores.

6. Method according to claim 1 or 2, wherein the at least one component (10; 25) is embedded in a longitudinal end region of the product to be cast.

7. Method according to claim 3, wherein the at least one component (10; 25) is embedded in a longitudinal end region of the product to be cast.

8. Method according to claim 4, wherein the at least one component (10; 25) is embedded in a longitudinal end region of the product to be cast.

9. Method according to claim 1 or 2, wherein the method is an extruder-type slip casting method or a slip-former-type slip casting method.

10. The method according to claim 3, wherein the method is an extruder-type slip casting method or a slip-former-type slip casting method.

11. The method according to claim 4, wherein the method is an extruder-type slip casting method or a slip-former-type slip casting method.

12. The method according to claim 6, wherein the method is an extruder-type slip casting method or a slip-former-type slip casting method.

13. An apparatus (1; 21) for casting precast concrete products with a substantially horizontal slip-form casting process, wherein the apparatus comprises feeding means (2; 22, 23) for feeding concrete material to a slip-form casting mould (4, 5, 6) in at least one feeding stage, which slip-form casting mould (4, 5, 6) compacts and defines the product to be cast,

characterized in that the apparatus (1; 21) comprises a single embedding device (9; 24) for embedding at least one component (10; 25) in the concrete mass via the upper surface of the concrete product to be cast after the at least one feeding phase and before the top surface (6) of the slip-form casting mould (4, 5, 6) compacts the upper surface of the product to be cast,

wherein the embedding direction of the single embedding device (9; 24) for embedding the at least one component (10; 25) in the concrete material is adjustable and the position of the embedding device is adjusted by tilting the embedding device relative to the apparatus, which tilting takes place about a tilting axis which extends horizontally and perpendicularly relative to the casting direction.

14. Apparatus (1; 21) according to claim 13, wherein the slip-form casting mould (4, 5, 6) comprises a top surface (6) divided into sections, between which sections a gap is provided for allowing a partially embedded part (10; 25) to pass through the slip-form casting mould.

15. An apparatus (1; 21) according to claim 13 or 14, wherein the apparatus (1; 21) comprises an air-core forming device (11).